1. Field
Disclosed herein is a vacuum belt conveyor for transferring veneer sheets.
2. Description of Related Art
The basic structure of the vacuum belt conveyor is conventional, i.e. it consists of an elongated box structure whose interior can be brought under a vacuum effect. At least one lane-like perforation extends along the bottom of the box through which the bottom area of the box can be brought under the vacuum effect prevailing inside the case. The lane is bounded by a conveyor belt running at its both edges in dragging contact with the lower surface of the vacuum box. The product to be conveyed, such as a veneer sheet, is brought, at its upper surface, under the vacuum effect through the openings, the sheet thus being moved by the belts to the intended place where it is released from the vacuum effect by stamping by means of kicker arms provided in the conveyor.
Vacuum belt conveyors have been used to transfer veneer sheets, among other things, even as embodiments in which the veneer sheet lies on the conveyor. A vacuum inside the conveyor affects the lower surface of the veneer sheet holding the sheet pressed against the belts that convey the sheet. Even in these embodiments the belt are placed adjacent to a vacuum area to bound the vacuum area.
The problem with these conveyors has been, particularly when applied to the conveyance of veneer sheets, that different kinds of pieces of sheet end up in the perforation and remain there interfering with the vacuum effect. The perforations must be cleaned at regular intervals, in which operation the usual practice is to stop the devices creating the vacuum in the box. This results in an immediate interruption in the production.